GREEN PYTHON TAXONOMY – AS OF 2009

NOW THERE ARE 2 SPECIES AND 2 MORE SUBSPECIES

These are:

Chondropython viridis (Schlegel 1872), southern New Guinea generally and offshore Islands.

Chondropython viridis shireenae Hoser 2003, Australia only.

Chondropython viridis adelynhoserae Hoser 2009, Normanby Island, New Guinea.

Chondropython azureus Meyer 1875, New Guinea north of the central range, including offshore islands.

Many authors call Green Pythons “Morelia viridis”.

The following is taken from the paper:

Hoser, R. T. 2009. Creationism and contrived science: A review of recent python systematics papers and the resolution of issues of taxonomy and nomenclature.
Australasian Journal of Herpetology 2 (2009):1-34.

CHONDROPYTHON MEYER 1874

Designation of so-called “Green Pythons” in the genus Chondropython has been the normal situation among taxonomists for most of the past 100 years.  Having said this, in recent times a number of taxonomists lump the Green Pythons in the genus Morelia, noting the obvious affinities between the two groups.

Hobbyists still call the snakes “Chondro’s” regardless of what scientific name they use.

Allowing for the latter placement of these snakes in the supergenus “Morelia”, these snakes remain outside the core Morelia group of “Carpet Pythons”, with the Australiasis snakes (so-called Scrub Pythons) also forming a different group.

If one doesn’t accept the obvious splits to include the genera Australiasis, Lenhoserus and Chondropython, then all preceding names are available at the subgenus level.

For the purposes of this paper and following on from Hoser 2000b, Chondropython is treated here as a full genus.

Rawlings and Donellan (2003) in their Phylogeographic Analysis of the Green Python, yielded results in accordance with similar studies for other snake genera with similar cross New Guinea distributions, including Acanthophis (Hoser 1998), Leiopython (Hoser 2000) and Australiasis (Harvey et. al. 2000).

While Hoser 1998 and Hoser 2000b did not relate the findings with geological evidence in terms of seeking explanations for results, other authors including Harvey et. al. (2000) have.

That is that as a result of the formation and uplifting of the central New Guinea range commencing about 5 million years before present, species were split into allopatric groups which in turn speciated, giving the present day results.

Hence the barriers affecting one species seems to have similarly affected others, giving a near mirror image distribution patterns for the various python genera (as diagnosed by Hoser 2000b) and also perhaps elapid groups as well.

That Rawlings and Donellan found evidence to support two species of Green Python was not a surprise and had been anticipated by hobbyist keepers for decades.

They wrote:

“The pattern of relationships found for mitochondrial and nuclear genes suggests the presence of two species of M. viridis, one present north of the central cordillera and the other present in Southern New Guinea and Australia.”

Their mtDNA evidence in terms of the outlier Australian population concurred with Hoser 2000b and McDowell 1975 in that while it had clear affinities to the southern New Guinea snakes, they were derived from them in relatively recent geological time and by a migration south from the main population.

Hobbyist keepers in Europe and the USA were well aware of the different pattern morphs from different locations over many years, including differences between those from north and south of the main dividing range.

While Rawlings and Donellan 2003 didn’t concern themselves with nomenclature of the regional forms of Green Python, all taxa have been named at the species level.  This contradicts Rawlings et. al. 2008, p. 604, who state the northern New Guinea taxon is “unnamed”, when in fact it was named in 1875 by Meyer.
Furthermore one of two obvious subspecies, the Australian Green Python (Chondropython viridis shireenae) Hoser 2003 has also been named.

A second highly distinct form of Green Python, hitherto unnamed and from Normanby Island, Milne Bay Province, PNG, is formally described for the first time here as the subspecies Chondropython viridis adelynhoserae subsp. nov.

That these snakes differ from other Chondropython has been speculated for some time.  However until recently I had not seen any specimens in life or good quality photos of specimens in life.  DNA evidence as provided by Rawlings and Donnellan 2003 also supports the hypothesis that these snakes differ from other Chondropython and are reproductively isolated from them and have been for some time.

For the record, Chondropython pulcher Sauvage 1878, is a synonym of C. azureus Meyer 1875 being derived from the same general region as C. azureus.

Chondropython viridis Adelynhoserae subsp. nov.

Holotype: A specimen in the Australian Museum R129716, from Normanby Island, Milne Bay, Papua New Guinea.

Diagnosis: This is the form of Green Python restricted to Normanby Island, Milne Bay Province, PNG.

It is separated from all other Chondropython in New Guinea and Australia by it’s adult dorsal pattern of (smallish) white blotches that in the main do not cover the spinal ridge, as seen in all other Australian and other PNG Chondropython.

Sometimes Chondropython from elsewhere will have similar blotches, but invariably, these snakes either also have a mid-dorsal line or dots (not seen in adelynhoserae), or the blotches run well over the spinal (mid dorsal) mid-line.

MtDNA for the holotype was examined by Rawlings and Donellan 2003 and compared with other Chondropython yielding traits broadly in line with C. viridis viridis (but a three per cent sequence divergence) (see p. 41 their paper).  Having said that, it also shared five nucleotide substitutions that would otherwise be synapomorphies of the northern lineage, one of which is an indel.

This result in terms of mtDNA and base pair analysis, as published by Rawlings and Donellan 2003, forms an additional and/or alternative diagnostic means of identifying and separating C. v. adelynhoserae subsp. nov. from other Chondropython.

In other words, the taxon C. v. adelynhoserae subsp. nov. can be separated from other C. viridis by the degree of base pair separation/divergence of mtDNA and/or nuclear DNA as detailed by Rawlings and Donellan 2003.

This is the only Chondropython taxon found on Normanby Island, Milne Bay Province, PNG and is allopatric to all other C. viridis or C. azureus.

Etymology: Named after the elder daughter of this author, Adelyn (pronounced: Adder-lyn) Hoser, in honor of her valuable education work at educational reptile demonstrations and the like, including from the age of five safely handling venomoid versions of the world’s five deadliest snake genera, namely Parademansia, Oxyuranus, Pseudonaja, Notechis and Acanthophis and most importantly after five years of doing so, never having had a single bite! This emphatically proves that the best way to avoid snakebites is to be nice to them.

CHONDROPYTHON SUMARY

Based on what is now believed to be allopatric distribution and factors outlined elsewhere, the named taxa of Green Python are now as follows:

Chondropython viridis (Schlegel 1872), southern New Guinea generally and offshore Islands.

Chondropython viridis shireenae Hoser 2003, Australia only.

Chondropython viridis adelynhoserae subsp. nov. (this paper), Normanby Island, New Guinea.

Chondropython azureus Meyer 1875, New Guinea north of the central range, including offshore islands.

Maxwell (2005), gave detailed information about local “races” of Chondropython, including from islands.  However noting the extreme phenotypic variation of the genus and the non-sampling of intermediate populations (when available), and the added variables of local adaptations to altitude and so on resulting in localized colour variants and the like, there is no evidence that any of the forms identified in the book warrant recognition beyond the taxa (to subspecies level) identified in this paper based on available evidence, most notably that of Rawlings and Donnellan 2003.

Notwithstanding this, the book remains mandatory reading for those with an interest in the genus.

The above is taken from the paper:

Hoser, R. T. 2009. Creationism and contrived science: A review of recent python systematics papers and the resolution of issues of taxonomy and nomenclature.
Australasian Journal of Herpetology 2 (2009):1-34.

Click on the above text to download the paper in full.

Webpage keywords include:Green Python Chondropython viridis, Australia, Australian, Chondropython viridis shireenae, Chondropython azureus is from Northern New Guinea, species and subspecies, Chondropython adelynhoserae is from Normanby Island, PNG, Meyer, Hoser, 2009, Hoser 2003, Green Tree Python, Chondropython nominate form is from southern New Guinea and nearby Islands